Hot Air Blower

ABSTRACT

A hot air blower includes a shell including a fan mechanism, a combustion device, a vane mechanism, and a flame protector disposed therein. The vane mechanism includes a clipping seat and a plurality of guiding vanes extended thereon. The plurality of guiding vanes extend obliquely and prevents the air passing through the vane mechanism from generating turbulence. The clipping seat and the flame protector form a half-closed combustion chamber therebetween. Heat in the half-closed combustion chamber causes a thermal expansion of the air and, thereby increasing a speed and a volume of the air passing the guiding vanes of the vane mechanism. Heated air is discharged from an external flow tube and which controls a heating range of an area of the hot air blower.

CROSS REFERENCE

The present application is a continuation-in-part application of U.S. patent application Ser. No. 13/629,729, filed on Sep. 28, 2012, of which the entire disclosure is incorporated herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hot air blower and, particularly to, a hot air blower improved to blow air in a more focused and less spread manner and to allow a user to effectively control the extent of airflow.

2. Description of the Related Art

U.S. Pat. No. 7,065,899 discloses a gas hot air gun including a main body, an air blower, an ignition device, a nozzle and a switch set. The main body includes a barrel, a handle, a heating chamber and a mixing chamber on the inner front of the barrel. A battery set and a gas can are inside the handle. One end of the nozzle is connected to the gas can. The switch set includes a power switch and an ignition switch. Users press the power switch and have gas spray out from the nozzle into the heating chamber to generate heat. The blower sends out hot air in the heating chamber out of the main body. A metal slice to regulate the direction of air and a catalyst to avoid flames from coming out of the nozzle area are inside the heating chamber.

Applicant finds his patented gas hot air gun can be further improved to have better controls of gas flow rates and heating temperatures. It is acknowledged that there may be situations in which a high gas flow rate inhibits a flame from being ignited, and when the gas flow rate and oxygen supply rate are increased in order to achieve a higher heating temperature, the increased supply of oxygen proportionally causes air to travel at a higher speed as the gas hot air gun includes an air passage with a fixed cross sectional area. However, air can blow out a flame when the burning speed of oxygen is slower or the density of gas is low.

The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art.

SUMMARY OF THE INVENTION

According to the present invention, a hot air blower includes a shell, and a fuel canister, a fan mechanism, a combustion device, a vane mechanism, and a flame protector are disposed within the shell. The fan mechanism blows air. The combustion device includes a burning end for giving out heat of combustion. The vane mechanism is disposed in a position making the combustion device locate between the fan mechanism and the vane mechanism. The vane mechanism includes a clipping seat and a plurality of guiding vanes. Each of the plurality of guiding vanes extend obliquely on the clipping seat to prevent air passing through the vane mechanism from generating turbulence and to achieve a flow-regulating effect. The clipping seat and the plurality of guiding vanes are formed as a one-piece structure. The flame protector is disposed in the vane mechanism and hoods the burning end of the combustion device. The air passing the vane mechanism is able to be expelled out of the flame protector. The clipping seat and the flame protector form a half-closed combustion chamber therebetween. Heat in the half-closed combustion chamber causes a thermal expansion of the air and thereby increasing a speed and a volume of the air passing the guiding vanes of the vane mechanism. An external flow tube is fixed in and extended out of the shell. Heated air discharged out of the hot air blower from the external flow tube and which controls a heating range of an area of the hot air blower.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

Other objects, advantages, and new features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanied drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hot air blower in accordance with a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the hot air blower of FIG. 1.

FIG. 3 is a partial, exploded perspective view of the hot air blower of FIG. 1.

FIG. 4 is a cross-sectional view of the hot air blower of FIG. 1.

FIG. 5 is another cross-sectional view of the hot air blower of FIG. 1.

FIG. 6 is a cross-sectional view showing the hot air blower of FIG. 1 in operation.

FIG. 7 is another cross-sectional view showing the hot air blower of FIG. 1 in operation.

FIG. 8 is a cutout view showing the hot air blower of FIG. 1 in operation.

FIG. 9 is a perspective view of a hot air blower in accordance with a second embodiment of the present invention.

FIG. 10 is an exploded perspective view of the hot air blower of FIG. 9.

FIG. 11 is a partial, exploded perspective view of the hot air blower of FIG. 9.

FIG. 12 is a perspective view showing the hot air blower of FIG. 9 and a fuel canister engagable therewith.

FIG. 13 is a continued perspective view of FIG. 12 and shows the hot air blower in engagement with the fuel canister.

FIG. 14 is a cross-sectional view showing the hot air blower of FIG. 9 in operation.

FIG. 15 is a cutout view showing the hot air blower of FIG. 9 in operation.

FIG. 16 is a perspective view of a hot air blower in accordance with a third embodiment of the present invention.

FIG. 17 is an exploded perspective view of the hot air blower of FIG. 16.

FIG. 18 is another exploded perspective view of the hot air blower of FIG. 16.

FIG. 19 is a cross-sectional view showing the hot air blower of FIG. 16 in operation.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 through 8 show a hot air blower in accordance with a first embodiment of the present invention. The hot air blower includes a shell 10, a fuel canisterister 20, a fan mechanism 30, a combustion device 40, a vane mechanism 50, a flame protector 60, a internal flow tube 70, and an external flow tube 80. The shell 10 includes first and second outer shells 11 and 12 symmetrically joined to each other. The first and second shells 11 and 12 include first and second clamping collars 13 and 14 disposed therein. The shell 10 is substantially T-shaped including first and second extensions 101 and 102 transverse to each other. The fan mechanism 30, the combustion device 40, the vane mechanism 50, and the flame protector 60 are disposed in the first section 101 of the shell 10. The fuel canister 20 is disposed in the second section 102 of the shell 10.

The fuel canister 20, the fan mechanism 30, the combustion device 40, the vane mechanism 50, and the flame protector 60 are disposed within the shell 10.

The fan mechanism 30 blows air. The fan mechanism 30 includes a fan 31, a flow-regulating sleeve 32, a fan motor 33, and a shielding cover 34. The flow-regulating sleeve 32 includes a first end encasing the fan 31. The flow-regulating sleeve 32 includes a hole extended therethrough, and the fan 31 is disposed in the hole and at the first end and of the flow-regulating sleeve 32. The fan 31 is completely disposed within the hole of the flow-regulating sleeve 32, but not regarded as limiting. The flow-regulating sleeve 32 includes a second end covering the fan motor 33. The fan motor 33 is disposed in the hole of the flow-regulating sleeve 32. The fan motor 33 is not completely disposed within the hole of the flow-regulating sleeve 32, but not regarded as limiting. The fan 31 is connected with and driven by the fan motor 33. The shielding cover 34 includes an end attached to the flow-regulating sleeve 32. The fan motor 33 includes a motor spindle 331 the fan 31 is connected thereto. The fan 31 is rotated upon rotation of the motor spindle 331. The shielding cover 34 is attached to the second end of the flow-regulating sleeve 32. The flow-regulating sleeve 32 and the shielding cover 34 are in a tandem arrangement. The flow-regulating sleeve 32 includes an annular internal wall 321, an annular external wall 322, and a plurality of fins 323 extending between the internal and external walls 321 and 322. The plurality of fins 323 extends obliquely on the internal wall 321 and radially from the internal wall 321 to the external wall 322. The internal wall 321 delimits a bore 324. The bore 324 includes the fan motor 33 tightly fitted therein.

Combustions is carried out in the combustion device 40. A catalyst net 41 can tame and prevent a flame from extending out of the combustion device 40. The combustion device 40 includes an end connecting with a first fuel line 42 and another end defining a burning end 43. The burning end 43 gives out heat of combustion. The combustion device 40 is mounted on the vane mechanism 50.

The vane mechanism 50 includes a first clipping seat 51 a flow-regulating net 52, a second clipping seat 53, a plurality of guiding vanes 54, and a heating tube 55. The first clipping seat 51 includes a bottom side 511, and a first through hole 513 is extended through the bottom side 511. The first through hole 513 is disposed in a central position of the first clipping seat 51. The combustion device 40 is insertably disposed through the first through hole 513. A plurality of guide holes 514 are disposed circumferentially around the first through hole 513. An ignition wire 516 is connected with an ignition device 517 disposed on the first clipping seat 51. The ignition device 517 is able to produce a flame. The flow-regulating net 52 is received within the first clipping seat 51. The flow-regulating net 52 includes a plurality of meshes 521. The flow-regulating net 52 includes a second through hole 522. The second through hole 522 corresponds to the first through hole 513. The combustion device 40 is insertably disposed through the first and second through holes 513 and 522. The flow-regulating net 52 is made of metal. The second clipping seat 53 is formed separately from the first clipping seat 51. One of the first and second clipping seats 51 and 53 includes a first lateral side 512 extended annularly and along a circumference of the bottom side 511 and including a plurality of protruded first clamping sections 515. The other of the first and second clipping seats 51 and 53 includes a second lateral side 531 extended annularly and including a plurality of recessed second clamping sections 532, as well as defining an embedding wall 533. The first and second clipping seats 51 and 53 are connected together with the plurality of protruded first clamping sections 515 correspondingly engaged with the plurality of recessed second clamping sections 532. The first and second clipping seats 51 and 53 are engaged together and hold the plurality of guiding vanes 54. Each of the plurality of guiding vanes 54 includes a recessed hook section 541 and an anti-disengagement protruded hook section 542 on the same side and adjacent to each other. The recessed hook section 541 of each of the plurality of guiding vanes 54 is hooked onto the embedding wall 533. The anti-disengagement protruded hook sections 542 of each of the plurality of guiding vane 54 is engaged and being clamped between one of the plurality of protruded first clamping sections 515 and one of the plurality of recessed second clamping sections 532, thereby preventing disengagement from the first and second clipping seats 51 and 53. Each of the plurality of guiding vanes 54 also includes a recessed limiting section 543. The recessed limiting section 543, the recessed hook section 541, and the anti-disengagement protruded hook section 542 are on the same side and adjacent to one another. The heating tube 55 mounted on and disposed in the first clipping seat 51. The heating tube 55 is U-shaped. The heating tube 55 includes an end defining a fixing end 551. The heating tube 55 is insertably disposed through and includes the fixing end 551 fixed in one of the plurality of guide holes 514. The heating tube 55 includes two legs extended separately, with one leg connecting with the first fuel line 42 and the other leg connecting with a second fuel line 552, respectively. The heating tube 55 is disposed in front of the fan mechanism 30 and aside of the combustion device 40. The combustion device 40 is able to give off heat energy to the heating tube 55 and prevents fuel condensed and clogged therein. Therefore, the heating tube 55 has a better combustion efficiently. The shielding cover 34 includes a lateral side extended annularly and delimiting a cavity and including a cutout 341 penetrating therethrough. The cutout 341 allows the ignition wire 516 and the second fuel line 552 to extend therethrough.

The flame protector 60 is mounted on the vane mechanism 50 and hoods the burning end 43 of the combustion device 40. The flame protector 60 is axially disposed with respect to the vane mechanism 50. The flame protector 60 includes a side extended annularly and delimiting a cavity, and has an end defining an open end 61 and another end defining an air exit end 62. The exit end 62 has a wall and an orifice extended through the wall. The burning end 43 of the combustion device 40 is hooded in the cavity and disposed adjacent to the open end 61 of the flame protector 60. The open end 61 of the flame protector 60 is fixed to the second clipping seat 53 of the vane mechanism 50. The flame protector 60 has an end fixed to the lateral side 531 of the second clipping seat 53. Therefore, the flame protector 60 is mounted on the vane mechanism 50. In the embodiment, the second clipping seat 53 and the flame protector 60 are fixed together by a fastener. Moreover, the second clipping seat 53 is disposed between the first clipping seat 51 and the flame protector 60. The flame protector 60 also includes the wall including a plurality of vents 63 extended therethrough, and the air passing the vane mechanism 50 flows out of the flame protector 60 through the plurality of vents 63. The plurality of vents 63 allow heat convection and tames the flame. Therefore, the flame from the combustion device 40 is prevented from propagation through the flame protector 60. The plurality of vents 63 are circumferentially disposed on the flame protector 60 and are parallel to one another. Moreover, the first and second clipping seats 51 and 53 and the flame protector 60 form a half-closed combustion chamber a therebetween.

The internal flow tube 70 is disposed within the shell 10. The first and second clamping collars 13 and 14 cooperate together to hold the internal flow tube 70 fixed inside the shell 10. The internal flow tube 70 includes a periphery delimiting a cavity, and the combustion device 40 and the vane mechanism 50 are disposed in the cavity of the internal flow tube 70. The internal flow tube 70 is disposed between the fan mechanism 30 and the external flow tube 80. Additionally, the shielding cover 34 is disposed between the flow-regulating sleeve 32 and the internal flow tube 70.

The external flow tube 80 controls a heating range of an area of the hot air blower. The external flow tube 80 has one end mounted in the shell 10 and another end extended out of the shell 10. The external flow tube 80 includes a first end 81 mounted on the internal flow tube 70 and a second end 82 extended out of the shell 10. Moreover, the external flow tube 80 includes a cavity extended therethrough from the first end to the second end 81 and 82 thereof, and the flame protector 60 is extended in the cavity of external flow tube 80.

Furthermore, the internal and external flow tubes 70 and 80 form a plurality of gaps b between junctions therebetween.

When the hot air blower is in operation, the air flows through the plurality of guide holes 514 and is regulated by the plurality of meshes 521 of the flow-regulating net 52. The flow-regulating net 52 limits the amount of air passing the vane mechanism 50 per unit time to achieve a flow-regulating effect. Each of the plurality of guiding vanes 54 extends obliquely between the first and second clipping seats 51 and 53. The plurality of guiding vanes 54 are circumferentially arranged on the first and second clipping seats 51 and 53. The plurality of guiding vanes 54 prevent the air passing through the vane mechanism 50 from generating turbulence to achieve a flow-regulating effect. Heat in the half-closed combustion chamber a would cause a thermal expansion of the air, thereby increasing a speed and a volume of the air passing the guiding vanes 54 of the vane mechanism 50. The internal flow tube 70 keeps the air flowing therein. The heated air would be discharged out of the hot air blower from the external flow tube 80. The plurality of gaps b causes a venturi effect allowing an increased amount of external air to flow therein. Furthermore, the plurality of gaps b prevents impedance of circulation of the air avoiding the flame being put off, particularly when a user operates the hot air blower too close to an object to be heated.

FIGS. 9 through 15 show a hot air blower in accordance with a second embodiment of the present invention, and same numbers are used to correlate similar components of the first embodiment, but bearing a letter a. The second embodiment is modified from the first embodiment such that the first and second embodiments differentiate from each other in that a shell 10 a does not enclose a fuel canister 20 a engaged therewith. The shell 10 includes a second extension 102 a to which the fuel canister 20 a is joined. Also, a fan mechanism 30 a does not include the shielding cover 34. In addition, the vane mechanism 50 includes the first and second clipping seats 51 and 53, but a vane mechanism 50 a includes a clipping seat 56 a, and the clipping seat 56 a and a plurality of guiding vane 54 a are formed as a one-piece structure. Furthermore, each of the plurality of vanes 54 a extends obliquely, and the plurality of guiding vanes 54 a are circumferentially arranged on the outer circumference of the clipping seat 56 a. Therefore, since the clipping seat 56 a and the plurality of guiding vanes 54 a are formed as a one-piece structure, the vane mechanism 50 a has a better structure strength and longer life, and a user can install the vane mechanism 50 a more easily. Moreover, the hot air blower includes a flame protector 60 a and a tamer 64 a disposed in the flame protector 60 a. The flame protector 60 a defines an open end 61 a and an air exit end 62 a, and includes a plurality of vents 63 a circumferentially disposed and extended therethrough. The tamer 64 a is made of metal and includes a plurality of meshes. The tamer 64 a is in the form of a tube. The tamer 64 a retards heat loss, thereby enabling a combustion device 40 a of the hot air blower to emit heat stably and at a stable speed. The tamer 64 a can also prevent the flame from the combustion device 40 a from spreading out of the flame protector 60 a. The clipping seats 56 a and the flame protector 60 a form a half-closed combustion chamber a therebetween. In addition, the arrangements between the combustion device 40, the vane mechanism 50, the flame protector 60, the internal flow tube 70, and the external flame tube 80 also apply to the second embodiment. Furthermore, the shell 10 a includes first and second clamping collars 13 a and 14 a disposed therein holding an internal tube 70 a securely.

FIGS. 16 through 19 show a hot air blower in accordance with a third embodiment of the present invention and same numbers are used to correlate similar components of the first embodiment, but bearing a letter b. The third embodiment is modified from the first embodiment, and the first and third embodiments differentiate from each other in that a fan mechanism 30 b does not include the shielding cover 34. Also, a vane mechanism 50 b of the hot air blower of the third embodiment includes a clipping seat 56 b instead of two clipping seats. The clipping seat 56 b includes a plurality of guiding vanes 54 b, and the clipping seat 56 b and a plurality of guiding vane 54 b are formed as a one-piece structure. Each of the plurality of guiding vanes 54 b extends obliquely, and the plurality of guiding vanes 54 b are circumferentially arranged on the outer circumference of the clipping seat 56 b. Therefore, since the clipping seat 56 b and the plurality of guiding vanes 54 b are formed as a one-piece structure, the vane mechanism 50 b has a better structure strength and longer life, and a user can also install the vane mechanism 50 a more easily. Moreover, the flame protector 60 b differentiates from the flame protector 60. The flame protector 60 b defines an open end 61 b and an air exit end 62 b including a plurality of meshes. The plurality of meshes of the air exit end 62 b of the flame protector 60 b are made of metal. Further, a ring (not numbered) is used to keep the flame protector 60 b on the clipping seat 56 b stably. In addition, the hot air blower of the third embodiment also includes a shell 10 b enclosing a fuel canister 20 b engaged therewith. The fuel canister 20 is joined to a second extension 102 b of the shell 10 b. A fan 31 b is received in a flow-regulating sleeve 32 b. A combustion device 40 defines a burning end 43 b hooded by a flame protector 60 b. An internal flow tube 70 and an external flow tube 80 are in a tandem arrangement. The arrangements between the combustion device 40, the vane mechanism 50, the flame protector 60, the internal flow tube 70, and the external flame tube 80 also apply to the third embodiment, except that the hot air blower of the third embodiment includes a heating tube 55 b disposed outside the clipping seat 56 b and adjacent to the plurality of guiding vanes 54 b.

In view of the foregoing, the flame protectors 60, 60 a, and 60 b are axially disposed with respect to the vane mechanisms 50, 50 a, and 50 b, respectively. The plurality of vents 63, 63 a allows the heated air in the half-closed combustion chamber a to flow thereout. The combustion devices 40, 40 a, and 40 b and the vane mechanism 50, 50 a, and 50 b are insertably disposed in the internal flow tubes 70, 70 a, and 70 b, respectively. The external flow tubes 80, 80 a, and 80 b are extended out of the shell 10, 10 a, and 10 b, respectively. The air can flow spirally, and cold and hot air can be thoroughly mixed, and the heated air can be discharged out at a predetermined angle in order to control a heating range of an area of the hot air blower. The half-closed combustion chamber a would be less affected by the speed of the flow outside, thereby providing a greater heating range of an area. Furthermore, since the vane mechanisms 50, 50 a, and 50 b can reduce backflow, thereby enabling a stable flow field inside and outside of the half-closed combustion chamber a and allowing the heated air to be spirally discharged. Therefore, it would be easier for a user to control a heating range of an area in this regard. Each of the plurality of guiding vanes 54, 54 a, and 54 b is obliquely extended at an angle determined from the rotation speed of the respective fan mechanisms 30, 30 a, and 30 b, thereby stabling a spiral flow field and reducing backflow and turbulence and increasing air flow stability and efficiency. The air flows at higher speed at a zone radially outward of a center of the spiral flow field and at slower speed at a zone towards the center. Furthermore, since the flame protectors 60, 60 a, and 60 b cover the respective combustion device 40, 40 a, and 40 b, and the half-closed combustion chamber a is close to the center of the spiral flow field where the air flows slower, supply of oxygen and the speed of air can be stably controlled in an internal area of the respective flame protectors 60, 60 a, and 60 b when the hot air blower blows a greater amount of air and needs greater combustion. Furthermore, since the plurality of guiding vanes 54, 54 a, and 54 b are disposed away from the center of the spiral flow field where the air flows faster, and conform to a streamline curvature of the spiral flow field, drag can be effectively reduced to the least and backflow can be effectively reduced and cold and hot air can be mixed thoroughly.

While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of invention, and the scope of invention is only limited by the scope of accompanying claims. 

What is claimed is:
 1. A hot air blower comprising: a shell; a fuel canister, a fan mechanism, a combustion device, a vane mechanism, and a flame protector disposed within the shell, with the fan mechanism blowing air, with the combustion device including a burning end for giving out heat of combustion, with the vane mechanism disposed in a position making the combustion device locate between the fan mechanism and the vane mechanism, with the vane mechanism including a clipping seat and a plurality of guiding vanes, with each of the plurality of guiding vanes extending obliquely on the clipping seat and make as a one-piece structure to prevent air passing through the vane mechanism from generating turbulence and to achieve a flow-regulating effect; with the flame protector disposed in the vane mechanism and hooding the burning end of the combustion device, with the air passing the vane mechanism able to be expelled out of the flame protector, with the clipping seat and the flame protector forming a half-closed combustion chamber therebetween, with heat in the half-closed combustion chamber causing a thermal expansion of the air and thereby increasing a speed and a volume of the air passing the guiding vanes of the vane mechanism; and an external flow tube fixed in and extended out of the shell, with heated air discharged out of the hot air blower from the external flow tube and which controls a heating range of an area of the hot air blower.
 2. The hot air blower as claimed in claim 1, wherein the plurality of vents are circumferentially disposed on the flame protector.
 3. The hot air blower as claimed in claim 1 further comprising an internal flow tube disposed within the shell, wherein the internal flow tube includes a periphery delimiting a cavity, and the combustion device and the vane mechanism are disposed in the cavity of the internal flow tube, and the external flow tube includes a first end fixed to the internal flow tube and a second end extended out of the shell.
 4. The hot air blower as claimed in claim 3, wherein the flow tube includes a cavity extended therethrough from the first end to the second end thereof, and the flame protector is extended in the cavity of external flow tube.
 5. The hot air blower as claimed in claim 1, wherein the combustion device is connected with a first fuel line, and the clipping seat includes a heating tube mounted thereon.
 6. The hot air blower as claimed in claim 5, wherein the heating tube includes two legs extended separately with one leg connected with the first fuel line and the other leg connected with a second fuel line respectively.
 7. The hot air blower as claimed in claim 6, wherein the heating tube is disposed in front of the fan mechanism and aside of the combustion device, and the combustion device is able to give off heat energy to the heating tube and prevent fuel condensed and clogged therein.
 8. The hot air blower as claimed in claim 6, wherein the heating tube is disposed outside the clipping seat and adjacent to the plurality of guiding vanes.
 9. The hot air blower as claimed in claim 6, wherein the heating tube is disposed in the clipping seat.
 10. The hot air blower as claimed in claim 1, wherein the shell includes first and second outer shells symmetrically joined to each other.
 11. The hot air blower as claimed in claim 10, wherein the first and second shells include first and second clamping collars disposed therein and holding the internal flow tube fixedly inside the shell.
 12. The hot air blower as claimed in claim 1, wherein the fan mechanism includes a fan and a flow-regulating sleeve, encasing the fan.
 13. The hot air blower as claimed in claim 1, wherein the shell is substantially T-shaped and includes first and second extensions transverse to each other, and the fan mechanism, the combustion device, the vane mechanism, and the flame protector are disposed in the first section of the shell.
 14. The hot air blower as claimed in claim 13, wherein the fuel canister is joined to the second section of and disposed outside the shell.
 15. The hot air blower as claimed in claim 13, wherein the fuel canister is joined to the second section of and received in the shell.
 16. The hot air blower as claimed in claim 3, wherein the internal and external flow tubes form a plurality of gaps between junctions therebetween.
 17. The hot air blower as claimed in claim 2, wherein the flame protector includes a tamer disposed therein, and the flame protector defines an open end and an air exit end, and the tamer is in the form of a tube and includes a plurality of meshes.
 18. The hot air blower as claimed in claim 1, wherein the flame protector defines an open end and an air exit end including a plurality of meshes.
 19. The hot air blower as claimed in claim 18 further comprising an internal flow tube disposed within the shell, wherein the internal flow tube includes a periphery delimiting a cavity, and the combustion device and the vane mechanism are disposed in the cavity of the internal flow tube, and the external flow tube includes a first end fixed to the internal flow tube and a second end extended out of the shell.
 20. The hot air blower as claimed in claim 1 further comprising an internal flow tube disposed within the shell, wherein the internal flow tube includes a periphery delimiting a cavity, and the combustion device and the vane mechanism are disposed in the cavity of the internal flow tube, and the external flow tube includes a first end fixed to the internal flow tube and a second end extended out of the shell. 